Determinants in tRNA for activation of arginyl-tRNA synthetase: Evidence that tRNA flexibility is required for the induced-fit mechanism
Determinants in tRNA for activation of arginyl-tRNA synthetase: Evidence that tRNA flexibility is required for the induced-fit mechanism
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DOI：
10.1021/bi051575h
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发表时间：
2005-12-20
期刊：
影响因子：
2.9
通讯作者：
Mirande, M
中科院分区：
文献类型：
--
作者：
Guigou, L;Mirande, M
精氨酰-tRNA合成酶（ArgRS）催化tRNA依赖性反应中的精氨酰-腺苷酸的形成。以往的研究表明，tRNA结合后会发生构象变化。在这项研究中，我们分析的序列和结构特征的tRNA是必不可少的激活哺乳动物的乙酰-tRNA合成酶的催化中心。在这里，提出了具有不同激活剂潜力的tRNA变体。对ArgRS激活至关重要的三个区域是末端腺苷、D环和tRNA的反密码子茎环。ArgRS的Add-1 N-末端结构域在氨酰-tRNA合成酶中具有非常独特的性质，可与tRNA凸侧角上的D-环相互作用，在锚定tRNA和参与tRNA诱导的氨基酸活化中具有重要作用。结果表明，锁定的受体末端，反密码子环，和D-环的tRNA的催化，反密码子结合，和添加-1域的ArgRS也需要一些灵活性的tRNA分子，提供G：U碱基对，以实现生产构象的酶的活性位点的诱导适合。
Arginyl-tRNA synthetase (ArgRS) catalyzes formation of arginyl-adenylate in a tRNA-dependent reaction. Previous Studies have revealed that conformational changes Occur upon tRNA binding. In this study, we analyzed the sequence and structural features of tRNA that are essential to activate the catalytic center of mammalian arginyl-tRNA synthetase. Here, tRNA variants with different activator potential are presented. The three regions that are crucial for activation of ArgRS are the terminal adenosine, the D-loop, and the anticodon stem-loop of tRNA. The Add-1 N-terminal domain of ArgRS, which has the very unique property among aminoacyl-tRNA synthetases to interact with the D-loop in the corner of the convex side of tRNA, has an essential role in anchoring tRNA and participating in tRNA-induced amino acid activation. The results suggest that locking the acceptor extremity, the anticodon loop, and the D-loop of tRNA on the catalytic, anticodon-binding, and Add-1 domains of ArgRS also requires some flexibility of the tRNA molecule, provided by G:U base pairs, to achieve the productive conformation of the active site of the enzyme by induced fit.